— It be Jack who is in the office.— No it be him. I saw him off at the airport half an

问题补充：

— It be Jack who is in the office.

— No, it be him. I saw him off at the airport half an hour ago.

A. can’t ; can’t

B. must; can’t

C. must; mustn’t

D. may; mustn’t

答案：

A. can’t ; can’t

(答案→)B. must; can’t

C. must; mustn’t

D. may; mustn’t

解析：must表推测只用于肯定句；在否定句和疑问句中用can。